The present invention pertains to feeding a web of collations as part of the processing of a mailing system, and more particularly to feeding a web from a first module that center-slits the web into side-by-side portions, to later modules of the mailing system where the sheets of the two webstreams are accumulated.
A web is a continuous stream of forms separated by transverse lines of weakening called perforations. Generally, having documents in web form versus individual separate documents increases throughput in various types of document handling systems. Thus, many different types of document handling systems, such as printers and inserter systems, have been adapted to accommodate webs.
A web is often processed by an inserter system. Inserter systems are well known in the art and are generally used by organizations to facilitate producing a large volume of mailings. Often, the input to an inserter system is a web of computer-generated and printed documents where each document contains information intended for a particular addressee.
It is the function of the inserter system to accept the web and to produce individual mailings that correspond to each document. To accomplish this, a typical inserter includes a variety of modules, each for performing a different task. There are often various web handling modules (slitters, cutters and bursters) for separating the continuous streams of forms into singular or discrete documents, an accumulator module for assembling discrete documents into a collation, a folder module for folding the collation into a desired configuration (such as a Z-fold, C-fold or half-fold), feeder modules for adding sheets to the collation, and an inserter station module for inserting the collation into an envelope.
Although such prior art systems as described above generally perform well, problems exist when handling certain types of webs in some applications. Some webs are comprised of forms that are approximately 11 by 18 inches in dimension and are joined along their major length to form the web of continuous forms. Thus, the major length of the forms is transverse to the longitudinal dimension of the web. Accordingly, this allows a computer printer to create two 8.5 by 11 inch printouts or documents side-by-side on each web form. Inserter systems incorporate an upstream web slitter module to cut the web along its longitudinal center line so as to create two side-by-side web portions. In this instance, each side-by-side web portion contains 8.5 by 11 inch forms that are joined along their minor length. Once the web has been slit along its center line, the next downstream operation is typically to separate the now smaller web forms into discrete documents. To achieve this, either a burster module or a cutter module is used. The burster module separates the forms by tearing them off from one another along the perforations. Thus, the perforations assist the bursting operation. In contrast, the cutter module separates the forms from one another by cutting along or near the perforations without assistance from the perforations. Although slitting the web to create side-by-side web portions is relatively easy, interfacing the two web portions with the adjacent downstream module of the inserter, whether it is a burster module or a cutter module, presents difficulties.
Most burster modules and cutter modules accept two web portions in what is commonly referred to as xe2x80x9c2-upxe2x80x9d orientation. In this arrangement, two web streams are fed into the burster or cutter module in upper-lower relationship, i.e. one web portion over the other web portion. This is in direct contrast to the side-by-side relationship of the two web portions as they exit the slitter module. Thus, operational difficulties are created when interfacing the slitter module to an adjacent downstream burster or cutter module. As the two web portions emerge from the slitter module, the two portions are first separated and then directed so as to bring one portion over the other.
The xe2x80x9c2-upxe2x80x9d burster and cutter modules typically feed each of the two web portions in alternating-collation fashion, feeding all of a collation on one side, and then all of another collation on the other side, and so on. When the two streams of web first reach the burster or cutter module, it selects one or the other side to process. While it is processing the side first selected, the forms conveyor continues to feed both sides. Thus, the other side of the web builds up in front of the burster or cutter, while the first side is being processed. Depending on the length of the collations being processed, the result is that sometimes the buildup is excessive and causes paper handling problems, some problems being caused because the takeup by the burster or cutter imparts a jerky motion to the web, disordering the buildup.
What is needed is a system for feeding a 2-up, north-south formatted web to a cutter or burster in a way that avoids having an excessive length of one side of the web from accumulating in an uncontrolled way while the other side is processed by the cutter or burster.
Accordingly, the present invention provides a system and corresponding method for assembling collation sets from a split web consisting of two webstreams, each providing a series of collations of connected sheets, the method including the steps of: alternately selecting the two webstreams and from the selected webstream drawing a sheet to a cutting or bursting station; cutting or bursting the sheet to separate it from the webstream; conveying the sheet to an accumulating station where sheets are accumulated; monitoring the sheet for determining whether the sheet is a beginning or an end of a collation; and ejecting the sheets accumulated from the selected webstream based on the determining of whether the sheet is the beginning or the end of a collation.
In a further aspect of the method, the step of determining whether the sheet is the beginning or the end of a collation is performed based on a barcode on the sheet indicating, in one embodiment, that the sheet is the last sheet in a collation, and in another embodiment, that the sheet is the first sheet in a next collation.
The system corresponding to the method of the present invention, again for assembling collation sets from a split web, the split web consisting of two webstreams each providing a series of collations of connected sheets, includes: a cutter or burster, responsive to the two webstreams, for drawing a sheet alternately from each webstream to a respective port, for providing a cut or burst sheet; a conveyor, responsive to the cut or burst sheet, for conveying the cut or burst sheet to an accumulating station; a dual accumulator, responsive to the cut or burst sheet at the accumulating station, for accumulating the sheet in an accumulating area; means for monitoring the sheet for determining whether the sheet is a beginning or an end of a collation; and means for ejecting a collation in an accumulating area based upon the determining of whether the sheet is the beginning or the end of a collation.